1. Technical Field
The present invention relates to a gas-liquid contact apparatus, and more especially, to a reactive distillation apparatus for multistage counter-current rotating bed and its application which can be widely applied in absorption, distillation, reactive distillation, catalytic distillation, purification and preparation of the nano materials in the fields such as chemical, petrochemical, pharmaceutical and light industry.
2. Description of Related Art
Reactive distillation is a chemical operation process that couples the chemical reaction and the distillation process in the same equipment, which is more and more widely applied in chemical industry. Comparing with traditional reaction and distillation technology, the reactive distillation technology has obvious advantages: (1) Reaction and distillation processes are completed in the same equipment, thus lowering investment and operation costs, and conserving energy; (2) The simultaneous implementation of the reaction and distillation not only improves the distillation property, but also increases the reaction conversion and selectivity with the aid of the separation of the distillation; by immediately moving away the reaction product, it can overcome the limit of the chemical equilibrium conversion of the reversible reaction or increase the selectivity of consecutive or parallel reaction; (3) Easy to control temperature to prevent a hot spot; (4) Shorten the reaction time and improve the productivity. However, since the reactive distillation is accompanied with a chemical reaction, separation and interaction with a violent reaction, it complicates the engineering design of the process and affects many aspects. Moreover, most reactive distillation technologies studied at present draw on the experience of the traditional column form, restricted by the Earth gravity field, the mass-transfer efficiency is hard to improve greatly, thus limiting the application of the reactive distillation technology. Conducting deeper research about the reactive distillation technology, developing a new process based on the reactive distillation technology to replace many backward production processes domestically and developing an equipment structure and catalyst component with independent intellectual property have become important issues in the evolvement of the reactive distillation technology.
High gravity technology is a breakthrough technology to enhance transmission and heterogeneous reaction processes by means of the properties of the highly-enhanced mass transfer process in a high gravity environment and the homogeneous micromixing process so as to replace the chemical column equipment tens of meters high with the high gravity machine which is lower than two meters. Thus, the high gravity rotating bed is known as “the transistor of the chemical industry”. The high gravity rotating bed overcomes the shortcomings of the traditional column equipment. Under the action of centrifugal force hundreds of times or thousands of times higher than the gravity field of the Earth, the liquid phase flows to the outer ring in the form of liquid drops, liquid film and liquid filament on the filler surface. Then the wet area of the carrier increases, the liquid mixes evenly, the interfacial area increases and updates quickly, thus leading to the interphase mass transfer speed ratio up by 1-3 orders of magnitude in comparison to the traditional column. In this way, the mass transfer, heat transfer and the reactive process controlled by the liquid phase are greatly enhanced, the unit height of the mass transfer reduces by 1-2 orders of magnitude and many advantages not available in the traditional equipment are demonstrated.